| Lateral pterygoid muscle | |
|---|---|
 The Pterygoidei; thezygomatic arch and a portion of theramus of the mandible have been removed (labeled as "pterygoideus externus", visible in pink at center) | |
 Sagittal section of thetemporomandibular joint (labeled as "pterygoideus externus", visible in gray at bottom left) | |
| Details | |
| Origin | Superior head:infratemporal surface of sphenoid bone.Inferior head:lateral pterygoid plate |
| Insertion | Superior head: anterior side of the mandibular condyle.Inferior head:pterygoid fovea |
| Artery | Pterygoid branches of maxillary artery |
| Nerve | Lateral pterygoid nerve frommandibular nerve |
| Actions | Depresses and protrudes mandible, side to side movement of mandible |
| Identifiers | |
| Latin | musculus pterygoideus lateralis, musculus pterygoideus externus |
| TA98 | A04.1.04.006 |
| TA2 | 2109 |
| FMA | 49015 |
| Anatomical terms of muscle | |
Thelateral pterygoid muscle (orexternal pterygoid muscle) is a muscle ofmastication. It has two heads. It lies superior to themedial pterygoid muscle. It is supplied bypterygoid branches of themaxillary artery, and thelateral pterygoid nerve (from themandibular nerve, CN V3). It depresses and protrudes themandible. When each muscle works independently, they can move the mandible side to side.
The lateral pterygoid muscle has an upper head and a lower head.[1][2]
It lies superior to themedial pterygoid muscle.
The lateral pterygoid muscle is supplied bypterygoid branches of themaxillary artery.[citation needed]
The lateral pterygoid muscle is supplied by thelateral pterygoid nerve, a branch of themandibular nerve (CN V3), itself a branch of thetrigeminal nerve (CN V).
The primary function of the lateral pterygoid muscle is to pull the head of the condyle out of themandibular fossa along the articular eminence to protrude themandible.[2] A concerted effort of the lateral pterygoid muscles helps in lowering the mandible and opening the jaw. Unilateral action of a lateral pterygoid muscle causes contralateral excursion (a form ofmastication), usually performed in concert with themedial pterygoids.[citation needed] When they work independently, they can move the mandible side to side.[2]
Unlike the other three muscles of mastication, the lateral pterygoid alone can assist in depressing the mandible (opening the jaw). At the beginning of this action it is assisted by thedigastric,mylohyoid andgeniohyoid muscles.
The lateral pterygoid muscle may be involved intemporomandibular joint dysfunction.[1][2]
